1. Field of the Invention
The present invention relates to a device which is temporarily anchored within heart tissue for applying electrical stimuli to the heart. More specifically, the present invention is directed to a bipolar epicardial temporary pacing lead.
2. Description of the Prior Art
Heretofore various devices have been proposed for fixing a pacing lead to heart tissue by making an incision through the chest wall and then implanting an electrode within the myocardium of the heart wall. Examples of such previously proposed body implantable electrodes are disclosed in the following U.S. Patents:
______________________________________ U.S. PAT. NO. PATENTEE ______________________________________ 3,244,174 Wesbey et al 3,333,045 Fisher et al 3,474,791 Bentov 4,144,889 Tyers et al 4,338,947 Williams et al 4,442,840 Wojciechowicz, Jr. 4,444,207 Robicsek ______________________________________
All the prior temporary electrode devices (i.e., temporary pacing leads) have utilized single conductors with each conductor having a curved needle at the end thereof for insertion into (for threading the electrode through) heart tissue such as the epicardium to implant an exposed portion of the lead (electrode) within the myocardium of the heart. Often it is desired to place two such electrodes in the heart to provide for bipolar pacing.
In this respect, it is common to supply an electrical signal from a pulse generator in a pacer through one wire conductor to an electrode fixed to the myocardium so that the signal can pass through the myocardium causing the heart muscle to be depolarized and contract and then return by a second electrode also fixed to the myocardium and its wire conductor to the pacer having the pulse generator therein.
As will be described in greater detail hereinafter, the bipolar epicardial temporary pacing lead of the present invention differs from the previously proposed temporary pacing leads by providing a bipolar epicardial temporary pacing lead which has only one distal curved needle and one proximal percutaneous needle while at the same time providing two (bipolar) electrodes. Such bipolar epicardial temporary pacing lead requires only one puncture site at each end, thereby minimizing trauma to the heart and body wall.